Land snail Cylindrus obtusus (Draparnaud, 1805) is an endemic of Eastern Alps. The mollusk has very unusual for helicids pupilloid shell, but its reproductive tract is quite typical for the subfamily Ariantinae (Helicidae). Neither this species nor any similar forms are totally absent in fossil deposits (the earliest records of C. obtusus conventionally dated by the "pre-Pleistocene"). According to suggested hypothesis, this species is very young and was formed within the existing area at the end of Würm glaciation due to mutation of some representative of Ariantinae.

The ecological consequences of abnormal high water temperatures in summer 2010 on mussel Mytilus galloprovincialis and mytilaster Mytilaster lineatus colonies on the concrete traverses in coastal beach areas of the Odessa Bay (Lanzheron Cape, Northwestern Black Sea, Ukraine) has been studied. The negative impact of prolonged period of high water temperatures (up to 29-30ºC in the end of July and first half of August) reduced the density, biomass and share of mussels in total mass of biofouling from 3750 spec./ m2, 8.075 kg/m2 and 83.2% in June to 700 spec./m2, 0.410 kg/m2 and 23.8% in September, respectively. At the same time, mytilaster increased its density from 3280 to 6800 spec./m2, biomass from 0.481 to 0.672 kg/m2 and its share in biofouling from 7.6 to 49.8%. This demonstrates a higher tolerance to long-term periods of abnormal temperature conditions in mytilasters.

Slug Boettgerilla pallens was found in 4 localities in Crimea in 1987-1988. Three of these localities are situated in the urban landscapes on the south coast of Crimea. The fourth locality is in the natural mountain forest of the Crimean Nature Reserve. Short description of the slugs is given, reproductive system illustrated. The concomitant terrestrial molluscs are specified. The borders of B. pallens native range are discussed.

Results of ecological and zoogeographical study of the Middle Sarmatian gastropod molluscs of the Eastern Paratethys are presented. A comprehensive list of species and taxonomical remarks on some groups is provided. Some autecological characters of gastropods as well as the ratio of life forms with different diets are analyzed. The geographical areas of high abundance and maximal diversity of gastropods in the Eastern Paratethys correspond to the limits of bryozoan bioherms distribution; the latter are considered here as a chain of islands. Bryozoans served as edificatory factor for the Bessarabian Basin reef community in which gastropods played the leading role. The faunal characteristic is provided for the Sarmatian Bioherm Zoogeographical Province previously proposed by the authors. Malacofauna of the province is characterized by a high degree of endemism – around 55% of species and about 30% of genera are endemic. The distinctiveness of this zoogeographical unit started to form around end of the Early-Sarmatian time, it was most pronounced during the Middle Sarmatian (Bessarabian), and fauna became extinct during the freshening of the Sarmatian Basin during Late Sarmatian time. Taxonomic composition of gastropod fauna of different regions of the Middle Sarmatian (Bessarabian) Basin shows that Galician Gulf (West Ukraine and Moldavia) is the principal centre of diversity and origin of mollusks within the Eastern Paratethys and, perhaps, in the whole Sarmatian basin. This was caused by the fact of existence of bioherms at the Badenian and Early-Sarmatian time. A latitude gradient registered in the molluscs diversity – impoverishing from west to east connected with an asynchrony (retardation) of the bioherms formation in other regions i.e. Enikale Strait (Kerch and Taman peninsulas), Stavropol Strait (Central Ciscaucasus) and Mangyshlak Archipelago (northern part of Mangyshlak peninsula). The term ephemerous faunas is suggested for the Sarmatian and others shortly-lived endemic faunas of the Paratethys.

The shells of Oxychilus koutaisanus mingrelicus unknown earlier for Ukraine were discovered among the materials collected on the territory of the Donetsk Region in 1990-th. The unpdated information about the distribution on the territory of Ukraine of another Caucasian species, Stenomphalia ravergiensis , is provided. The presence of these species in the south-east of Ukraine can be result of the anthropochory.

The structure of reproductive tract of 15 species and subspecies (forms) of European (mainly Alpine) and South African Orculidae has been studied. For 12 of them the spermatophores were discovered and described or the characters undoubtedly indicating presence of spermatophore have been found (inner structure of the epiphallus). The presence of spermatophores as such is established for 5 species. Hypotheses about the possible historical relationships among subfamilies and genera of Orculidae and among species in the genus Orcula are presented.

The present-day data on geographical distribution and variability of three recent species of Aenigmomphiscola Kruglov et Starobogatov, 1981 (Lymnaeidae) are reviewed. More specific information concerning type series of two Aenigmomphiscola species is obtained. It is revealed that the species Ae. uvalievae and Ae. kazakhstanica cannot be distinguished in syntopy by their conchological traits, and, possible, these are conspecific. Judging from reliable records, the range of the genus Aenigmomphiscola covers a part of the East-European (Russian) plain, Southern Urals, the southern part of Western Siberia (including Altay), and Central Kazakhstan. Perhaps, representatives of the genus will be found in the future in another parts of Siberia and adjacent territories.

Critical review of stylommatophoran mollusks of the fauna of Vietnam. The Check-list includes 477 species and subspecies (96 genera, 20 families). For every species (subspecies) references to original description, synonymy, type locality (in original spelling) including synonyms, shell dimensions (for slugs – body length) and distributional data are given. In the end the index of mentioned molluscan names and the list of localities with geographic coordinates is placed.

Two parasitic gastropod species – Eulima bilineata Alder, 1848 and Odostomia turrita Hanley, 1844 – are recorded for the first time from the Murman coast of the Barents Sea. Brief species descriptions and their differences from similar species are provided. Certain hypotheses on frequent findings of new species on the Murman coast are discussed.

Limpet fauna of the Holarctic genus Acroloxus Beck, 1837 was examined in Lake Baikal. Morphology of protoconch and teleoconch of three species (A. baicalensis Kozhov, 1936, A. orientalis Kruglov et Starobogatov, 1991 and possible new Acroloxus species) was studied with SEM. Additional shell characters were described for A. baicalensis, collected from its type locality. Distribution of representatives of the genus Acroloxus in Lake Baikal and its basin was discussed.

The analysis of L. maximus allozymic variability on the Dnieper right-bank Ukraine territory testifies to the balanced proportion of homo- and heterozygotic genotypes in populations in most cases. Thus, this species is reproduced mostly amphimicticly. In some cases, probably, automixis takes place and leads to genotypes fixing in homozygotic state. This specis is characterized with stable chromosome numbers (n=31, 2n=62) and chromosome arms (NF=124). L. maximus morphometric parameters vary greatly but geographic tendencies this species morphological variability have not been found.

Shells of one of Physa Draparnaud, 1801 species, inhabiting the rivers and reservoirs of the North Azov Sea coast clearly fit the re-description and figures of North American Physa skinneri Taylor, 1954. The illustrated description of the species from Ukrainian populations is provided here; some data on its distribution in Ukraine and in entire Eurasia are discussed. It is quite possible that these Eurasian conchological «twin» for Ph. skinneri should be attributed to one of the Old World aborigine species. To solve this problem the type materials for most common European Physa species, as well as their variability, anatomy and other characteristics should be studied.

In June 2010 the new to the fauna of Belarus land snail species Brephulopsis cylindrica had been found. It is supposed that eventual way of penetration of this species is casual importing by railway transport. At present this population existing during some years.

Morphology of the slugs, variability of their coloration, external structure of the distal parts of reproductive system, internal structure of the atrium and oviduct were studied. The considerable inter- and intrapopulation variability of the ligula was revealed. The structure of spermatophores and their parts, separate stages of the mating behaviour of the slugs were shown. Short description of the life cycle is given. Morphological, anatomical and behaviour peculiarities of the Western-Ukrainian slugs from the Arion lusitanicus complex  are compared with the published data for Great Britain, France, Belgium, Germany and Poland.

Among a small collection of Polyplacophora from the Hans-Georg Müller collection at the Bavarian State collection we recognized an undescribed species of Leptochiton Gray, 1847, which is described herein. The species is minute (2.1 mm) and shows a strong sculpturing of roundish granules, quincuncially arranged on the tegmentum. The species’ small size, long intersegmental spicules, and the high tail valve with a concave postmucronal slope, easily separates this species from its congeners. In addition, based on the new material, we are able to raise the number of chiton species identified in Sri Lanka to 24, although three of them require further study. The former known species are compiled to make an easy tracing of the Sri Lanka chiton fauna possible. Within this evaluation we transferred the species Tonicia pectinoides Sykes, 1903 and Tonicia ceylonica Leloup, 1936 to the genus Lucilina, following the concept of Schwabe et al., [2008]. Besides the new species, Rhyssoplax maldivensis (E. A. Smith in Gardiner, 1903) and Acanthochitona leopoldi (Leloup, 1933), were the first time mentioned from Sri Lanka. Comparisons with the chiton faunas of the Andaman Sea area and the Maldives show that minimal species overlapping occurs, despite a similar species numbers in the three areas discussed.

Minute turriform conoideans comprise a considerable fraction of the taxonomically undescribed diversity of marine mollusks. Species of the genus Lienardia, Jousseaume, 1884, extremely diverse in shallow water tropical marine communities, have long been overlooked by taxonomists and a high proportion of them remain undescribed to date. Development of a specialized collection technique, based on deployment of lumun-lumun nets have provided a vast amount of material on this group and enable several new species to be distinguished. Examination of material from the Philippines and other regions of tropical Indo-Pacific revealed five new species of the genus Lienardia, which are being described as L. acrolineata, L. grandiradula, L. multicolor, L. roseangulata and L. tagaroae. Examination of radulae in described species of the genus Lienardia shown unexpected morphologic diversity. It suggests that either rapid morphological specialization of Lienardia members had taken place in the evolution of the genus, or similarity of shells in Lienardia species is possibly convergent.

During the study of the conchological variability of the land molluscs of the genus Chondrula in the south-east part of Ukraine and Crimea was discovered the form with specific structure of the aperture teeth which does not correspond to description of the known conchological forms of the widespread species Ch. tridens. The shells of Ch. tridens martynovi subsp. nov. with well developed aperture teeth are characterized by the following characters: 1) the angular tooth is not limited to the knoll or short comb on the aperture edge but sharply bends down and forms a low fold parallel to the parietal lamella; 2) palatal and suprapalatal teeth fuse to form the single well visible crestform lamella. Shells with incompletely formed teeth can resemble Ch. tridens tridens. The preliminary map of the distribution of Ch. tridens martynovi and Ch. tridens tridens on the territory of Ukraine was compiled on the basis of the materials of the State Museum of Natural History (Lviv). Brephulopsis konovalovae sp. nov. differs from B. bidens in shorter shells, more convex whorls and ribbed surface. The populations of B. konovalovae and B. bidens live sympatrically in the locus typicus in the mountain Crimea and do not form transitional forms.

During the investigation of the land mollusc fauna of the Donetsk upland (Eastern Ukraine) and adjoining territories three new species of the genus Helicopsis were discovered. One of them, H. subfilimargo sp. nov., is similar conchologically to Crimean H. filimargo, but clearly differs from it in a number of anatomical characters. The photographs illustrate the intrapopulation variability of the conchological and some anatomical features of H. subfilimargo sp. nov., H. martynovi sp. nov., H. luganica sp. nov. The conchological variability and some peculiarities of the internal structure of H. dejecta from Donetsk upland and adjoining territories are also demonstrated.

Population genetic structure of the land snails of the genus Brephulopsis (B. cylindrica and B. bidens) and their hybrids has been studied using of three polymorphic loci of esterases of foot tissues. Genetic patterns of allozyme variability of hybrid forms were similar to those for B. bidens. A similar result is obtained when using multilocus genotypes allozymes. On the other hand, the hybrid forms are characterized by an intermediate (“chimerical”) shell morphology between the two parental species. The values of effective population size were estimated by the Slatkin method of “private” alleles and the Kohn’s rarefaction curve method. These values were in the range from 20 to 60 individuals. 

Morphology of the soft body, copulative apparatus and taxonomically significant part of intestine of slugs from southern Magadan Region was examined. Basing on published and original data four species were recorded — Deroceras (Deroceras) laeve (Müller, 1774), D. (Agriolimax) altaicum (Simroth, 1886), D. (A.) agreste (Linnaeus, 1758) and D. (A.) reticulatum (Müller, 1774) introduced on Tauy Bay shore. Morphological characters of Far Eastern and Baikalian specimens of D. altaicum are discussed.